S10E34: Penchant for Poison
Three seemingly unrelated deaths proved to be serial murders. The killer had been careful – he used poison which had no taste or odor. Fortunately for investigators, it also had a unique chemical signature.
Previous Episode 
Season 1
The Disappearance of Helle Crafts
S1E1 / 21 Apr 1996
The Magic Bullet
S1E2 / 03 Oct 1996
The House That Roared
S1E3 / 10 Oct 1996
The Footpath Murders
S1E4 / 17 Oct 1996
Planted Evidence
S1E5 / 24 Oct 1996
Southside Strangler
S1E6 / 31 Oct 1996
Legionnaires' Disease
S1E7 / 07 Nov 1996
The Wilson Murder
S1E8 / 14 Nov 1996
Deadly Neighborhoods
S1E9 / 21 Nov 1996
Insect Clues
S1E10 / 28 Nov 1996
Outbreak
S1E11 / 05 Dec 1996
The List Murders
S1E12 / 12 Dec 1996
Raw Terror
S1E13 / 19 Dec 1996
Season 2
The Common Thread
S2E1 / 02 Oct 1997
The Dirty Deed
S2E2 / 09 Oct 1997
Killer Fog
S2E3 / 16 Oct 1997
Sex, Lies & DNA
S2E4 / 23 Oct 1997
Bitter Potion
S2E5 / 30 Oct 1997
The Blood Trail
S2E6 / 06 Nov 1997
Fatal Fungus
S2E7 / 20 Nov 1997
Charred Remains
S2E8 / 13 Nov 1997
Something's Fishy
S2E9 / 04 Dec 1997
Sealed with a Kiss
S2E10 / 18 Dec 1997
Postal Mortem
S2E11 / 15 Jan 1998
Micro-Clues
S2E12 / 05 Feb 1998
Deadly Parasites
S2E13 / 05 Mar 1998
Season 3
Without a Trace
S3E1 / 01 Oct 1998
Knot for Everyone
S3E2 / 08 Oct 1998
The Talking Skull
S3E3 / 15 Oct 1998
Foreign Body
S3E4 / 22 Oct 1998
Deadly Delivery
S3E5 / 29 Oct 1998
'Sim'ilar Circumstances
S3E6 / 05 Nov 1998
Grave Evidence
S3E7 / 12 Nov 1998
Deadly Formula
S3E8 / 19 Nov 1998
Beaten by a Hair
S3E9 / 03 Dec 1998
Crime Seen
S3E10 / 17 Dec 1998
Speck of Evidence
S3E11 / 07 Jan 1999
Broken Bond
S3E12 / 14 Jan 1999
Out of the Ashes
S3E13 / 21 Jan 1999
Season 4
Invisible Intruder
S4E1 / 10 Jun 1999
The Killing Room
S4E2 / 01 Jul 1999
Ultimate Betrayal
S4E3 / 08 Jul 1999
Cement the Case
S4E4 / 22 Jul 1999
Innocence Lost
S4E5 / 15 Jul 1999
Til Death Do Us Part
S4E6 / 29 Jul 1999
Ties That Bind
S4E7 / 05 Aug 1999
Body of Evidence
S4E8 / 16 Sep 1999
Accident or Murder?
S4E9 / 19 Aug 1999
Core Evidence
S4E10 / 14 Oct 1999
Haunting Vision
S4E11 / 15 Dec 1999
With Every Breath
S4E12 / 22 Dec 1999
Slippery Motives
S4E13 / 29 Dec 1999
Season 5
Badge of Deceit
S5E1 / 12 Sep 2000
Dew Process
S5E2 / 19 Sep 2000
A Woman Scorned
S5E3 / 26 Sep 2000
A Voice from Beyond
S5E4 / 03 Oct 2000
Burning Ambition
S5E5 / 10 Oct 2000
Memories
S5E6 / 17 Oct 2000
Trail of Truth
S5E7 / 24 Oct 2000
Material Evidence
S5E8 / 31 Oct 2000
Kill'igraphy
S5E9 / 07 Nov 2000
Nursery Crimes
S5E10 / 14 Nov 2000
Lasting Impression
S5E11 / 21 Nov 2000
Foundation of Lies
S5E12 / 28 Nov 2000
Unholy Vows
S5E13 / 05 Dec 2000
Deadly Knowledge
S5E14 / 05 Dec 2000
Broken Promises
S5E15 / 12 Dec 2000
Time Will Tell
S5E16 / 19 Dec 2000
Second Shot at Love
S5E17 / 26 Dec 2000
Journey to Justice
S5E18 / 02 Jan 2001
Video Diary
S5E19 / 09 Jan 2001
Season 6
Missing in Time
S6E1 / 21 May 2001
Missing Pearl
S6E2 / 28 May 2001
Man's Best Friend?
S6E3 / 04 Jun 2001
Hand Delivered
S6E4 / 11 Jun 2001
Death Play
S6E5 / 18 Jun 2001
Fire Dot Com
S6E6 / 25 Jun 2001
Mistaken for Dead
S6E7 / 02 Jul 2001
Frozen Evidence
S6E8 / 09 Jul 2001
Soft Touch
S6E9 / 16 Jul 2001
Church Disappearance
S6E10 / 23 Jul 2001
Photo Finish
S6E11 / 30 Jul 2001
Whodunit
S6E12 / 06 Aug 2001
Horse Play
S6E13 / 13 Aug 2001
Treads and Threads
S6E14 / 20 Aug 2001
Killer's 'Cattle' Log
S6E15 / 27 Aug 2001
Skin of Her Teeth
S6E16 / 03 Sep 2001
Line of Fire
S6E17 / 10 Sep 2001
Bad Blood
S6E18 / 17 Sep 2001
Pure Evil
S6E19 / 24 Sep 2001
Root of All Evil
S6E20 / 01 Oct 2001
Where the Blood Drops
S6E21 / 08 Oct 2001
Punch Line
S6E22 / 15 Oct 2001
Sibling Rivalry
S6E23 / 22 Oct 2001
Pastoral Care
S6E24 / 29 Oct 2001
Bagging a Killer
S6E25 / 05 Nov 2001
Double Trouble
S6E26 / 12 Nov 2001
Cats, Flies, and Snapshots
S6E27 / 19 Nov 2001
Naked Justice
S6E28 / 26 Nov 2001
Treading Not So Lightly
S6E29 / 03 Dec 2001
Shopping Spree
S6E30 / 10 Dec 2001
Season 7
The Cheater
S7E1 / 01 Jan 2002
Forever Hold Your Peace
S7E2 / 08 Jan 2002
Reel Danger
S7E3 / 15 Jan 2002
Who's Your Daddy
S7E4 / 22 Jan 2002
The Alibi
S7E5 / 29 Jan 2002
A Bite Out of Crime
S7E6 / 05 Feb 2002
Purr-fect Match
S7E7 / 12 Feb 2002
Bio-Attack
S7E8 / 19 Feb 2002
A Shot in the Dark
S7E9 / 26 Feb 2002
Without a Prayer
S7E10 / 05 Mar 2002
A Clutch of Witnesses
S7E11 / 12 Mar 2002
Scout's Honor
S7E12 / 19 Mar 2002
A Touching Recollection
S7E13 / 26 Mar 2002
A Leg to Stand On
S7E14 / 10 Jul 2002
Partners in Crime
S7E15 / 17 Jul 2002
Within a Hair
S7E16 / 31 Jul 2002
Chief Evidence
S7E17 / 24 Jul 2002
A Bitter Pill to Swallow
S7E18 / 12 Sep 2002
Sip of Sins
S7E19 / 26 Aug 2002
Telltale Tracks
S7E20 / 27 Aug 2002
Ghost in the Machine
S7E21 / 28 Aug 2002
Frozen in Time
S7E22 / 29 Aug 2002
Cold Storage
S7E23 / 30 Aug 2002
The Metal Business
S7E24 / 26 Sep 2002
Dressed to Kill
S7E25 / 04 Sep 2002
Palm Print Conviction
S7E26 / 03 Oct 2002
A Vow of Silence
S7E27 / 10 Oct 2002
Elephant Tracks
S7E28 / 17 Oct 2002
A Bag of Evidence
S7E29 / 31 Oct 2002
Tooth or Consequences
S7E30 / 07 Nov 2002
The Sniffing Revenge
S7E31 / 14 Nov 2002
Sleight of Hand
S7E32 / 21 Nov 2002
Scratching the Surface
S7E33 / 28 Nov 2002
Fire Proof
S7E34 / 05 Dec 2002
X Marks the Spot
S7E35 / 09 Dec 2002
All Charged Up
S7E36 / 10 Dec 2002
Breaking the Mold
S7E37 / 11 Dec 2002
House Call
S7E38 / 12 Dec 2002
Marathon Man
S7E39 / 13 Dec 2002
The Sniper's Trail
S7E40 / 19 Dec 2002
Plastic Fire
S7E41 / 22 Jan 2003
Last Will
S7E42 / 29 Jan 2003
Season 8
Dessert Served Cold
S8E1 / 02 Apr 2003
The Music Case
S8E2 / 09 Apr 2003
Paintball
S8E3 / 16 Apr 2003
Sign Here
S8E4 / 23 Apr 2003
Shadow of a Doubt
S8E5 / 30 Apr 2003
Tourist Trap
S8E6 / 04 Jun 2003
Once Bitten
S8E7 / 11 Jun 2003
All Wet
S8E8 / 18 Jun 2003
Shot of Vengeance
S8E9 / 25 Jun 2003
Dinner and a Movie
S8E10 / 23 Jul 2003
A Wrong Foot
S8E11 / 30 Jul 2003
Order Up
S8E12 / 06 Aug 2003
When the Dust Settled
S8E13 / 13 Aug 2003
A Welcome Intrusion
S8E14 / 27 Aug 2003
Within Arm's Reach
S8E15 / 25 Aug 2003
Private Thoughts
S8E16 / 26 Aug 2003
Brotherhoods
S8E17 / 28 Aug 2003
Hair of the Dog
S8E18 / 29 Aug 2003
Breaking News
S8E19 / 03 Sep 2003
All the World's a Stage
S8E20 / 10 Sep 2003
The Big Chill
S8E21 / 17 Sep 2003
Bound for Jail
S8E22 / 01 Oct 2003
Sphere of Influence
S8E23 / 08 Oct 2003
Nailed
S8E24 / 05 Nov 2003
Sign of the Zodiac
S8E25 / 03 Dec 2003
Letter Perfect
S8E26 / 10 Dec 2003
True Lies
S8E27 / 07 Jan 2004
Bed of Deceit
S8E28 / 21 Jan 2004
Smoke in Your Eyes
S8E29 / 14 Jan 2004
Flower Power
S8E30 / 28 Jan 2004
Past Lives
S8E31 / 18 Feb 2004
Over and Out
S8E32 / 25 Feb 2004
Death by a Salesman
S8E33 / 03 Mar 2004
Web of Seduction
S8E34 / 31 Mar 2004
Grounds for Indictment
S8E35 / 07 Apr 2004
Dueling Confessions
S8E36 / 21 Apr 2004
Traces of Truth
S8E37 / 05 May 2004
Honor Thy Father
S8E38 / 19 May 2004
Hack Attack
S8E39 / 04 Sep 2006
Deadly Curve
S8E40 / 10 Oct 2006
Visibility Zero
S8E41 / 15 Nov 2006
Flashover
S8E42 / 21 Dec 2006
Season 9
Road Rage
S9E1 / 02 Jun 2004
Hunter or Hunted
S9E2 / 09 Jun 2004
In Harm's Way
S9E3 / 16 Jun 2004
No Corpus Delicti
S9E4 / 23 Jun 2004
News at 11
S9E5 / 30 Jun 2004
Burning Desire
S9E6 / 07 Jul 2004
Cloak of Deceit
S9E7 / 14 Jul 2004
Bad Medicine
S9E8 / 21 Jul 2004
Stick 'em Up
S9E9 / 28 Jul 2004
Head Games
S9E10 / 04 Aug 2004
Making the Collar
S9E11 / 11 Aug 2004
Financial Downfall
S9E12 / 18 Aug 2004
A Daughter's Journey
S9E13 / 23 Aug 2004
Over a Barrel
S9E14 / 24 Aug 2004
Pinned by the Evidence
S9E15 / 24 Aug 2004
Cries Unheard
S9E16 / 25 Aug 2004
Buried Treasure
S9E17 / 26 Aug 2004
Badge of Betrayal
S9E18 / 22 Sep 2004
Deadly Matrimony
S9E19 / 29 Sep 2004
Muddy Waters
S9E20 / 13 Oct 2004
Point of Origin
S9E21 / 27 Oct 2004
Seeds for Doubt
S9E22 / 03 Nov 2004
Saving Face
S9E23 / 17 Nov 2004
Northern Exposure
S9E24 / 08 Dec 2004
Silk Stalkings
S9E25 / 29 Dec 2004
Fishing for the Truth
S9E26 / 12 Jan 2005
For Love or Money
S9E27 / 19 Jan 2005
South of the Border
S9E28 / 02 Feb 2005
The Stake-Out
S9E29 / 09 Feb 2005
Walking Terror
S9E30 / 02 Mar 2005
Season 10
Trial by Fire
S10E1 / 27 Apr 2005
Marked for Life
S10E2 / 18 May 2005
Plastic Puzzle
S10E3 / 01 Jun 2005
Up in Smoke
S10E4 / 29 Jun 2005
Soiled Plan
S10E5 / 06 Jul 2005
Headquarters
S10E6 / 13 Jul 2005
One for the Road
S10E7 / 20 Jul 2005
Army of Evidence
S10E8 / 27 Jul 2005
Shear Luck
S10E9 / 03 Aug 2005
Tagging a Suspect
S10E10 / 10 Aug 2005
Strong Impressions
S10E11 / 17 Aug 2005
Cereal Killer
S10E12 / 24 Aug 2005
Crash Course
S10E13 / 31 Aug 2005
A Leg Up on Crime
S10E14 / 07 Sep 2005
Tight-Fitting Genes
S10E15 / 14 Sep 2005
Deadly Valentine
S10E16 / 21 Sep 2005
Picture This
S10E17 / 28 Sep 2005
Oily in the Morning
S10E18 / 05 Oct 2005
Gold Rush
S10E19 / 12 Oct 2005
Four on the Floor
S10E20 / 19 Oct 2005
Writer's Block
S10E21 / 26 Oct 2005
A Clean Getaway
S10E22 / 02 Nov 2005
Prints Among Thieves
S10E23 / 09 Nov 2005
Unholy Alliance
S10E24 / 16 Nov 2005
Signed, Sealed & Delivered
S10E25 / 23 Nov 2005Cop Out
S10E26 / 14 Dec 2005
Summer Obsession
S10E27 / 21 Dec 2005
Enemy Within
S10E28 / 28 Dec 2005Elemental Clue
S10E29 / 04 Jan 2006
Moss, Not Grass
S10E30 / 11 Jan 2006
Material Witness
S10E31 / 08 Feb 2006
Garden of Evil
S10E32 / 22 Feb 2006
Sunday School Ambush
S10E33 / 08 Mar 2006
Penchant for Poison
S10E34 / 22 Mar 2006
Bump in the Night
S10E35 / 05 Apr 2006
Sole Searching
S10E36 / 12 Apr 2006
Murder on the Menu
S10E37 / 26 Apr 2006
Hot on the Trail
S10E38 / 10 May 2006
High 'n Dry
S10E39 / 31 May 2006
To the Viktor
S10E40 / 14 Jun 2006
Wired for Disaster
S10E41 / 21 Jun 2006
Wood-be Killer
S10E42 / 12 Jul 2006
Season 11
Naughty or Nyce
S11E1 / 19 Jul 2006
Going for Broke
S11E2 / 26 Jul 2006
Just Desserts
S11E3 / 02 Aug 2006
Sunday's Wake
S11E4 / 09 Aug 2006
Shattered Dreams
S11E5 / 16 Aug 2006
Dockter Visit
S11E6 / 23 Aug 2006
Murder, She Wrote
S11E7 / 30 Aug 2006
Concrete Alibi
S11E8 / 06 Sep 2006
Key Evidence
S11E9 / 13 Sep 2006
The Gambler
S11E10 / 20 Sep 2006
Weakest Link
S11E11 / 27 Sep 2006
Capitol Crimes
S11E12 / 04 Oct 2006
Undertaken
S11E13 / 11 Oct 2006
Dark Waters
S11E14 / 18 Oct 2006
Nice Threads
S11E15 / 25 Oct 2006
Grave Danger
S11E16 / 01 Nov 2006
Internal Affair
S11E17 / 08 Nov 2006
A Case of the Flue
S11E18 / 15 Nov 2006
No Safe Place
S11E19 / 22 Nov 2006
Live Wire
S11E20 / 29 Nov 2006
Van-ished
S11E21 / 06 Dec 2006
A Novel Idea
S11E22 / 13 Dec 2006
Chief Suspect
S11E23 / 20 Dec 2006
Water Hazard
S11E24 / 27 Dec 2006
Shell Game
S11E25 / 03 Jan 2007
Ring Him Up
S11E26 / 10 Jan 2007
Killer Impression
S11E27 / 17 Jan 2007
If I Were You
S11E28 / 24 Jan 2007
As the Tide Turns
S11E29 / 31 Jan 2007
A Tight Leash
S11E30 / 07 Feb 2007
Muffled Cries
S11E31 / 14 Feb 2007
Critical Maneuver
S11E32 / 21 Feb 2007
Skirting the Evidence
S11E33 / 28 Feb 2007
Small Town Terror
S11E34 / 07 Mar 2007
Fresh Heir
S11E35 / 14 Mar 2007
Ticker Tape
S11E36 / 21 Mar 2007
Step by Step
S11E37 / 28 Mar 2007
Blanket of Evidence
S11E38 / 04 Apr 2007
Fired-Up
S11E39 / 11 Apr 2007
Two in a Million
S11E40 / 18 Apr 2007
Bitter Brew
S11E41 / 25 Apr 2007
Message in a Bottle
S11E42 / 02 May 2007
Season 12
Sharper Image
S12E1 / 26 Sep 2007
Insulated Evidence
S12E2 / 03 Oct 2007
Cold Hearted
S12E3 / 10 Oct 2007
Wheel of Misfortune
S12E4 / 24 Oct 2007
Quite a Spectacle
S12E5 / 31 Oct 2007
Transaction Failed
S12E6 / 07 Nov 2007
The Day the Music Died
S12E7 / 14 Nov 2007
Sole Survivor
S12E8 / 19 Nov 2007
Insignificant Others
S12E9 / 10 Dec 2007
Catch 22
S12E10 / 17 Dec 2007
A Cinderella Story
S12E11 / 24 Dec 2007
Screen Pass
S12E12 / 07 Jan 2008
Pressed for Crime
S12E13 / 14 Jan 2008
Finger Pane
S12E14 / 21 Jan 2008
Good as Gold
S12E15 / 28 Jan 2008
Freedom Fighter
S12E16 / 13 Jun 2008
Dog Day Afternoon
S12E17 / 25 Feb 2008
Shattered Innocence
S12E18 / 07 Mar 2008
All Butt Certain
S12E19 / 14 Mar 2008
Jean Pool
S12E20 / 18 Apr 2008
Traffic Violations
S12E21 / 09 May 2008
Brotherly Love
S12E22 / 23 May 2008
Disrobed
S12E23 / 06 Jun 2008
Driven to Silence
S12E24 / 20 Jun 2008
Printed Proof
S12E25 / 28 Jun 2008
About Face
S12E26 / 18 Jul 2008
In the Bag
S12E27 / 25 Jul 2008
Yes, in Deed
S12E28 / 09 Feb 2008
Guarded Secrets
S12E29 / 22 Aug 2008
Smoking Out a Killer
S12E30 / 17 Feb 2008
Season 13
Frozen Assets
S13E1 / 12 Sep 2008
House Hunting
S13E2 / 19 Sep 2008
Shoot to Thrill
S13E3 / 03 Oct 2008
Political Thriller
S13E4 / 10 Oct 2008
Double Cross
S13E5 / 24 Oct 2008
Dancing with the Devil
S13E6 / 31 Oct 2008
Last Dance
S13E7 / 14 Nov 2008
Constructive Criticism
S13E8 / 21 Nov 2008
Home Evasion
S13E9 / 05 Dec 2008
Window Watcher
S13E10 / 12 Dec 2008
Stranger in the Night
S13E11 / 19 Dec 2008
Kidnapping
S13E12 / 09 Jan 2009
Sands of Crime
S13E13 / 20 Feb 2009
Calculated Coincidence
S13E14 / 06 Feb 2009
Sworded Scheme
S13E15 / 30 Jan 2009
Unmasked
S13E16 / 20 Feb 2009
Fashion Police
S13E17 / 13 Mar 2009
Church Dis-service
S13E18 / 03 Apr 2009
Seedy Intentions
S13E19 / 17 Apr 2009
DNA Dragnet
S13E20 / 15 May 2009
Smiley Face
S13E21 / 22 May 2009
Dirty Laundry
S13E22 / 05 Jun 2009
Drowning Sorrows
S13E23 / 12 Jun 2009
As Fault
S13E24 / 19 Jun 2009
Family Ties
S13E25 / 17 Jul 2009
Trouble Brewing
S13E26 / 24 Jul 2009
Holy Terror
S13E27 / 14 Aug 2009
Needle in a Haystack
S13E28 / 28 Aug 2009
Room with a View
S13E29 / 11 Sep 2009
Dollars and Sense
S13E30 / 25 Sep 2009
Hair Line
S13E31 / 02 Oct 2009
All That Glitters Is Gold
S13E32 / 16 Oct 2009
Deadly Rebellion
S13E33 / 30 Oct 2009
Sign of the Crime
S13E34 / 13 Nov 2009
Covet Thy Neighbor
S13E35 / 20 Nov 2009
Writing on the Wall
S13E36 / 04 Dec 2009
Hundreds of Reasons
S13E37 / 11 Dec 2009
Cold Feet
S13E38 / 18 Dec 2009
Separation Anxiety
S13E39 / 08 Jan 2010
Office Visit
S13E40 / 05 Mar 2010
Palm Saturday
S13E41 / 12 Mar 2010
Shoe-In for Murder
S13E42 / 19 Mar 2010
Family Interrupted
S13E43 / 02 Apr 2010
Runaway Love
S13E44 / 16 Apr 2010
Watchful Eye
S13E45 / 30 Apr 2010
Waste Mis-Management
S13E46 / 14 May 2010
Dirty Little Secret
S13E47 / 28 May 2010
Lights Out
S13E48 / 11 Jun 2010
Pet Rock
S13E49 / 25 Jun 2010
Best Foot Forward
S13E50 / 09 Jul 2010
Season 14
Purebread Murder
S14E1 / 16 Jul 2010
Hear No Evil
S14E2 / 30 Jul 2010
Hell's Kitchen
S14E3 / 13 Aug 2010
Three's a Crowd
S14E4 / 27 Aug 2010
A Squire's Riches
S14E5 / 10 Sep 2010
Home of the Brave
S14E6 / 24 Sep 2010
Freeze Framed
S14E7 / 08 Oct 2010
Touch of Evil
S14E8 / 17 Dec 2010
Textbook Murder
S14E9 / 31 Dec 2010
Filtered Out
S14E10 / 14 Jan 2011
Water Logged
S14E11 / 28 Jan 2011
Social Circle
S14E12 / 11 Feb 2011
Low Maintenance
S14E13 / 25 Feb 2011
Fate Date
S14E14 / 11 Mar 2011
Trail of a Killer
S14E15 / 25 Mar 2011
Gone Ballistic
S14E16 / 08 Apr 2011
Seeing Red
S14E17 / 22 Apr 2011
Auto-Motive
S14E18 / 06 May 2011
Skeleton Key
S14E19 / 20 May 2011
Funeral Services
S14E20 / 03 Jun 2011
Expert Witness
S14E21 / 17 Jun 2011
